Scope

Overview of in situ chemical oxidation (ISCO) as a remediation technology, including history of development and use, field applications, performance expectations, and costs.

Key Concepts

ISCO has had a long history of development and use. While research and development still continue, ISCO is a relatively mature technology for the remediation of contaminated groundwater, including source zones and plumes.

ISCO has primarily been applied for treatment of chlorinated organic solvents and petroleum hydrocarbons to achieve remediation objectives ranging from reducing contaminant mass in a source zone to achieving maximum contaminant levels in a plume. To achieve the more stringent remediation objectives, ISCO is almost always combined with another technology (e.g., bioremediation) or approach (e.g., monitored natural attenuation).

The effectiveness of ISCO varies and is highly dependent on proper site characterization and design of the oxidant delivery system to achieve oxidative destruction of contaminants of concern in a target treatment zone.

Typically ISCO applications require a targeted second or third oxidant delivery event since rebound in groundwater contaminant levels following cessation of active ISCO is a common occurrence.

The median cost of an ISCO project appears to be on the order of $100 per cubic yard treated. However, costs can vary widely depending on contaminant characteristics, site conditions, and the oxidant used.

When considering ISCO at a contaminated site, there are a number of frequently asked questions (Table 1.6) and key points to keep in mind to help support successful application (Table 1.7).